xref: /netbsd-src/usr.bin/seq/seq.c (revision 345cf9fb81bd0411c53e25d62cd93bdcaa865312) 
1 /*
2  * Copyright (c) 2005 The NetBSD Foundation, Inc.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to The NetBSD Foundation
6  * by Brian Ginsbach.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #ifndef lint
32 __COPYRIGHT("@(#) Copyright (c) 2005\
33  The NetBSD Foundation, Inc.  All rights reserved.");
34 __RCSID("$NetBSD: seq.c,v 1.13 2024/02/24 10:10:04 mlelstv Exp $");
35 #endif /* not lint */
36 
37 #include <ctype.h>
38 #include <err.h>
39 #include <errno.h>
40 #include <math.h>
41 #include <locale.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #define ZERO	'0'
48 #define SPACE	' '
49 
50 #define MAX(a, b)	(((a) < (b))? (b) : (a))
51 #define ISSIGN(c)	((int)(c) == '-' || (int)(c) == '+')
52 #define ISEXP(c)	((int)(c) == 'e' || (int)(c) == 'E')
53 #define ISODIGIT(c)	((int)(c) >= '0' && (int)(c) <= '7')
54 
55 /* Globals */
56 
57 const char *decimal_point = ".";	/* default */
58 char default_format[] = { "%g" };	/* default */
59 char default_format_fmt[] = { "%%.%uf" };
60 #define MAXPRECISION 40
61 
62 /* Prototypes */
63 
64 double e_atof(const char *);
65 
66 int decimal_places(const char *);
67 int numeric(const char *);
68 int valid_format(const char *);
69 
70 unsigned get_precision(const char *, unsigned);
71 char *generate_format(double, double, double, int, char, char *);
72 char *unescape(char *);
73 
74 unsigned
75 get_precision(const char *number, unsigned minprec)
76 {
77 	const char *p;
78 	unsigned prec;
79 
80 	p = strstr(number, decimal_point);
81 	if (p) {
82 		prec = strlen(number) - (p - number);
83 		if (prec > 0)
84 			prec -= 1;
85 		if (prec > MAXPRECISION)
86 			prec = MAXPRECISION;
87 	} else
88 		prec = 0;
89 
90 	return prec < minprec ? minprec : prec;
91 }
92 
93 /*
94  * The seq command will print out a numeric sequence from 1, the default,
95  * to a user specified upper limit by 1.  The lower bound and increment
96  * maybe indicated by the user on the command line.  The sequence can
97  * be either whole, the default, or decimal numbers.
98  */
99 int
100 main(int argc, char *argv[])
101 {
102 	int c = 0, errflg = 0;
103 	int equalize = 0;
104 	unsigned prec;
105 	double first = 1.0;
106 	double last = 0.0;
107 	double incr = 0.0;
108 	struct lconv *locale;
109 	char *fmt = NULL;
110 	const char *sep = "\n";
111 	const char *term = "\n";
112 	char pad = ZERO;
113 	char buf[6]; /* %.MAXPRECISIONf */
114 
115 
116 	/* Determine the locale's decimal point. */
117 	locale = localeconv();
118 	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
119 		decimal_point = locale->decimal_point;
120 
121 	/*
122          * Process options, but handle negative numbers separately
123          * least they trip up getopt(3).
124          */
125 	while ((optind < argc) && !numeric(argv[optind]) &&
126 	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
127 
128 		switch (c) {
129 		case 'f':	/* format (plan9) */
130 			fmt = optarg;
131 			equalize = 0;
132 			break;
133 		case 's':	/* separator (GNU) */
134 			sep = unescape(optarg);
135 			break;
136 		case 't':	/* terminator (new) */
137 			term = unescape(optarg);
138 			break;
139 		case 'w':	/* equal width (plan9) */
140 			if (!fmt)
141 				if (equalize++)
142 					pad = SPACE;
143 			break;
144 		case 'h':	/* help (GNU) */
145 		default:
146 			errflg++;
147 			break;
148 		}
149 	}
150 
151 	argc -= optind;
152 	argv += optind;
153 	if (argc < 1 || argc > 3)
154 		errflg++;
155 
156 	if (errflg) {
157 		fprintf(stderr,
158 		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
159 		    getprogname());
160 		exit(1);
161 	}
162 
163 	last = e_atof(argv[argc - 1]);
164 	prec = get_precision(argv[argc - 1], 0);
165 
166 	if (argc > 1) {
167 		first = e_atof(argv[0]);
168 		prec = get_precision(argv[0], prec);
169 	}
170 
171 	if (argc > 2) {
172 		incr = e_atof(argv[1]);
173 		prec = get_precision(argv[1], prec);
174 		/* Plan 9/GNU don't do zero */
175 		if (incr == 0.0)
176 			errx(1, "zero %screment", (first < last)? "in" : "de");
177 	}
178 
179 	/* default is one for Plan 9/GNU work alike */
180 	if (incr == 0.0)
181 		incr = (first < last) ? 1.0 : -1.0;
182 
183 	if (incr <= 0.0 && first < last)
184 		errx(1, "needs positive increment");
185 
186 	if (incr >= 0.0 && first > last)
187 		errx(1, "needs negative decrement");
188 
189 	if (fmt != NULL) {
190 		if (!valid_format(fmt))
191 			errx(1, "invalid format string: `%s'", fmt);
192 		fmt = unescape(fmt);
193 		if (!valid_format(fmt))
194 			errx(1, "invalid format string");
195 		/*
196 	         * XXX to be bug for bug compatible with Plan 9 add a
197 		 * newline if none found at the end of the format string.
198 		 */
199 	} else {
200 		if (prec == 0)
201 			fmt = default_format;
202 		else {
203 			sprintf(buf, default_format_fmt, prec);
204 			fmt = buf;
205 		}
206 		fmt = generate_format(first, incr, last, equalize, pad, fmt);
207 	}
208 
209 	if (incr > 0) {
210 		printf(fmt, first);
211 		for (first += incr; first <= last; first += incr) {
212 			fputs(sep, stdout);
213 			printf(fmt, first);
214 		}
215 	} else {
216 		printf(fmt, first);
217 		for (first += incr; first >= last; first += incr) {
218 			fputs(sep, stdout);
219 			printf(fmt, first);
220 		}
221 	}
222 	if (term != NULL)
223 		fputs(term, stdout);
224 
225 	return (0);
226 }
227 
228 /*
229  * numeric - verify that string is numeric
230  */
231 int
232 numeric(const char *s)
233 {
234 	int seen_decimal_pt, decimal_pt_len;
235 
236 	/* skip any sign */
237 	if (ISSIGN((unsigned char)*s))
238 		s++;
239 
240 	seen_decimal_pt = 0;
241 	decimal_pt_len = strlen(decimal_point);
242 	while (*s) {
243 		if (!isdigit((unsigned char)*s)) {
244 			if (!seen_decimal_pt &&
245 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
246 				s += decimal_pt_len;
247 				seen_decimal_pt = 1;
248 				continue;
249 			}
250 			if (ISEXP((unsigned char)*s)) {
251 				s++;
252 				/* optional sign */
253 				if (ISSIGN((unsigned char)*s))
254 					s++;
255 				continue;
256 			}
257 			break;
258 		}
259 		s++;
260 	}
261 	return (*s == '\0');
262 }
263 
264 /*
265  * valid_format - validate user specified format string
266  */
267 int
268 valid_format(const char *fmt)
269 {
270 	unsigned conversions = 0;
271 
272 	while (*fmt != '\0') {
273 		/* scan for conversions */
274 		if (*fmt != '%') {
275 			fmt++;
276 			continue;
277 		}
278 		fmt++;
279 
280 		/* allow %% but not things like %10% */
281 		if (*fmt == '%') {
282 			fmt++;
283 			continue;
284 		}
285 
286 		/* flags */
287 		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
288 			fmt++;
289 		}
290 
291 		/* field width */
292 		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
293 			fmt++;
294 		}
295 
296 		/* precision */
297 		if (*fmt == '.') {
298 			fmt++;
299 			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
300 				fmt++;
301 			}
302 		}
303 
304 		/* conversion */
305 		switch (*fmt) {
306 		    case 'A':
307 		    case 'a':
308 		    case 'E':
309 		    case 'e':
310 		    case 'F':
311 		    case 'f':
312 		    case 'G':
313 		    case 'g':
314 			/* floating point formats are accepted */
315 			conversions++;
316 			break;
317 		    default:
318 			/* anything else is not */
319 			return 0;
320 		}
321 	}
322 
323 	return (conversions <= 1);
324 }
325 
326 /*
327  * unescape - handle C escapes in a string
328  */
329 char *
330 unescape(char *orig)
331 {
332 	char c, *cp, *new = orig;
333 	int i;
334 
335 	for (cp = orig; (*orig = *cp); cp++, orig++) {
336 		if (*cp != '\\')
337 			continue;
338 
339 		switch (*++cp) {
340 		case 'a':	/* alert (bell) */
341 			*orig = '\a';
342 			continue;
343 		case 'b':	/* backspace */
344 			*orig = '\b';
345 			continue;
346 		case 'e':	/* escape */
347 			*orig = '\x1B';
348 			continue;
349 		case 'f':	/* formfeed */
350 			*orig = '\f';
351 			continue;
352 		case 'n':	/* newline */
353 			*orig = '\n';
354 			continue;
355 		case 'r':	/* carriage return */
356 			*orig = '\r';
357 			continue;
358 		case 't':	/* horizontal tab */
359 			*orig = '\t';
360 			continue;
361 		case 'v':	/* vertical tab */
362 			*orig = '\v';
363 			continue;
364 		case '\\':	/* backslash */
365 			*orig = '\\';
366 			continue;
367 		case '\'':	/* single quote */
368 			*orig = '\'';
369 			continue;
370 		case '\"':	/* double quote */
371 			*orig = '"';
372 			continue;
373 		case '0':
374 		case '1':
375 		case '2':
376 		case '3':	/* octal */
377 		case '4':
378 		case '5':
379 		case '6':
380 		case '7':	/* number */
381 			for (i = 0, c = 0;
382 			     ISODIGIT((unsigned char)*cp) && i < 3;
383 			     i++, cp++) {
384 				c <<= 3;
385 				c |= (*cp - '0');
386 			}
387 			*orig = c;
388 			--cp;
389 			continue;
390 		case 'x':	/* hexadecimal number */
391 			cp++;	/* skip 'x' */
392 			for (i = 0, c = 0;
393 			     isxdigit((unsigned char)*cp) && i < 2;
394 			     i++, cp++) {
395 				c <<= 4;
396 				if (isdigit((unsigned char)*cp))
397 					c |= (*cp - '0');
398 				else
399 					c |= ((toupper((unsigned char)*cp) -
400 					    'A') + 10);
401 			}
402 			*orig = c;
403 			--cp;
404 			continue;
405 		default:
406 			--cp;
407 			break;
408 		}
409 	}
410 
411 	return (new);
412 }
413 
414 /*
415  * e_atof - convert an ASCII string to a double
416  *	exit if string is not a valid double, or if converted value would
417  *	cause overflow or underflow
418  */
419 double
420 e_atof(const char *num)
421 {
422 	char *endp;
423 	double dbl;
424 
425 	errno = 0;
426 	dbl = strtod(num, &endp);
427 
428 	if (errno == ERANGE)
429 		/* under or overflow */
430 		err(2, "%s", num);
431 	else if (*endp != '\0')
432 		/* "junk" left in number */
433 		errx(2, "invalid floating point argument: %s", num);
434 
435 	/* zero shall have no sign */
436 	if (dbl == -0.0)
437 		dbl = 0;
438 	return (dbl);
439 }
440 
441 /*
442  * decimal_places - count decimal places in a number (string)
443  */
444 int
445 decimal_places(const char *number)
446 {
447 	int places = 0;
448 	char *dp;
449 
450 	/* look for a decimal point */
451 	if ((dp = strstr(number, decimal_point))) {
452 		dp += strlen(decimal_point);
453 
454 		while (isdigit((unsigned char)*dp++))
455 			places++;
456 	}
457 	return (places);
458 }
459 
460 /*
461  * generate_format - create a format string
462  *
463  * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
464  * when "%g" prints as "%e" (this way no width adjustments are made)
465  */
466 char *
467 generate_format(double first, double incr, double last,
468     int equalize, char pad, char *deffmt)
469 {
470 	static char buf[256];
471 	char cc = '\0';
472 	int precision, width1, width2, places;
473 
474 	if (equalize == 0)
475 		return deffmt;
476 
477 	/* figure out "last" value printed */
478 	if (first > last)
479 		last = first - incr * floor((first - last) / incr);
480 	else
481 		last = first + incr * floor((last - first) / incr);
482 
483 	sprintf(buf, deffmt, incr);
484 	if (strchr(buf, 'e'))
485 		cc = 'e';
486 	precision = decimal_places(buf);
487 
488 	width1 = sprintf(buf, deffmt, first);
489 	if (strchr(buf, 'e'))
490 		cc = 'e';
491 	if ((places = decimal_places(buf)))
492 		width1 -= (places + strlen(decimal_point));
493 
494 	precision = MAX(places, precision);
495 
496 	width2 = sprintf(buf, deffmt, last);
497 	if (strchr(buf, 'e'))
498 		cc = 'e';
499 	if ((places = decimal_places(buf)))
500 		width2 -= (places + strlen(decimal_point));
501 
502 	if (precision) {
503 		sprintf(buf, "%%%c%d.%d%c", pad,
504 		    MAX(width1, width2) + (int) strlen(decimal_point) +
505 		    precision, precision, (cc) ? cc : 'f');
506 	} else {
507 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
508 		    (cc) ? cc : 'g');
509 	}
510 
511 	return (buf);
512 }
513